TM 3-4230-218-12&PB-2.MAINTENANCE FUNCTIONS - Continued.f.Calibrate.To determine and cause corrections to be made or to beadjusted to Instruments or test, measuring, and diagnostic equipments used inprecision measurement.Consists of comparisons of two instruments, one ofwhich is a certified standard of known accuracy, to detect and adjust anydiscrepancy in the accuracy of the instrument being compared.g.Remove/Install.To remove and install the same item when requiredto perform service or other maintenance functions.Install may be the act ofemplacing, seating, or fixing into position a spare, repair part, or module(component or assembly) in a manner to allow the proper functioning of equip-ment or system.h.Replace.To remove an unserviceable item and install a serviceablecounterpart in its place.Replace " is authorized by the MAC and is shown asthe 3rd position code of the SMR code.i.Repair.The application of maintenance services,including faultlocation/troubleshooting, removal/installation, and disassembly/assembly proce-dures, and maintenance actions to identify troubles, and restore serviceabilityto an item by correcting specific damage, fault, malfunction, or failure in apart, subassembly, module (component or assembly) end item, or system.B-3.EXPLANATION OF COLUMNS IN THE MAC - SECTION II.a.Column1, GroupNumber.Column 1 lists functional group codenumbers,the purpose of which is to identify maintenance significant compo-nents, assemblies, subassemblies, and modules with the next higher assembly.End item group numbers shall be 00.b.Column2, Component/Assembly.Column 2 contains the names ofcomponents, assemblies, subassemblies, and modules for which maintenance isauthorized.c.Column3,MaintenanceFunction.performed on the item listed in Column 2.functions, see paragraph B-2.)d.Column4.MaintenanceCategory.Column 3 lists the functions to be(For a detailed explanation of theseColumn 4 specifies, by the listingof a work time figure in the appropriate subcolumn(s), the category of mainte-nance authorized to perform the function that maintenance function at theindicated category of maintenance.If the number or complexity of task withina listed maintenance function vary at different maintenance categories, appro-priate work time figures will be shown for each category.The work timefigure represents the average time required to restore an item (assembly,subassembly, component, module, end item, or system) to a serviceable condi-tion under typical field operating conditions.This time includes preparationtime (including any necessary disassembly/assembly time, troubleshooting/faultlocation time, and quality assurance/quality control time) in addition to thetime required to perform the specific tasks identified for the maintenancefunctions authorized in the maintenance allocation chart.The symbol desig-nations for the various maintenance categories are as follows:B-2